Enzymes
The biological catalysts that make life fast enough to happen, and why a fever is dangerous.
What this lesson covers
Enzymes is a 8-part Class 9 Biology lesson. Each part makes one point and then hands over to the next, so it can be read in a sitting or picked up again at the part you stopped on. It defines the idea in plain words before using it, works through an example step by step, breaks the topic into its parts and compares them, shows where it is used outside the textbook, names the mistakes that cost marks in an exam, ends with a recap of what to remember.
How it begins
An enzyme is a protein that speeds up a reaction without being used up. It is a biological catalyst. Without enzymes, the reactions that keep you alive would happen far too slowly to sustain you. Digesting a meal would take years. Two properties define them: They are specific, each works on one substrate. They are reusable: unchanged at the end.
The 8 parts
- What an enzyme is
- Lock and key
- Temperature and pH
- Explaining an experiment
- Enzymes at work
- Where marks get lost
- What to remember
- Watch one worked through
Practise Enzymes
Everything on QuizByt for Class 9 Biology that goes with this lesson: read it first, then test yourself while it is fresh.
🧠 5 quizzes on Enzymes (2 easy, 2 medium, 1 hard)
Work up from easy to hard: the hard quiz asks the Class 9 exam-style questions on Enzymes.
🖨️ Printable worksheet
Enzymes on paper for Class 9, with room to write the working out. Preview the first page free.
🎮 Games for Class 9 Biology
Memory and reasoning games at the right level for Class 9. Passing a quiz on Enzymes earns the credits that open them.
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